Maritime Technology and Research 2024; 6(4): 270227 https://doi.org/10.33175/mtr.2024.270227 Maritime Technology and Research 2024; 6(4): 270227 Maritime Technology and Research https://so04.tci-thaijo.org/index.php/MTR Research Article Assessment of water quality and heavy metal contamination in ballast water: Implications for marine ecosystems and human health Amarachi Paschaline Onyena 1 and Obioma Reuben Nwaogbe 2,* 1 Department of Environmental Management and Pollution Control, Nigeria Maritime University Okerenkoko, Warri, Delta State, Nigeria 2 Department of Transport and Nautical Science, Nigeria Maritime University Okerenkoko, Warri, Delta State, Nigeria Article information Abstract Received: January 21, 2024 1 st Revision: March 16, 2024 2 nd Revision: April 17, 2024 Accepted: April 28, 2024 Keywords Environmental impacts, Ecosystem disruption, Water Quality Assessment, Heavy Metal impact, Marine ecosystems, Human health The global menace of non-compliance with ballast water management poses a pressing environmental threat, as it facilitates the transfer of harmful organisms and sediment contaminants. This study investigates the environmental impact of ballast water discharged by ships, focusing on water quality and heavy metal concentrations. The release of ballast water, often containing elevated levels of heavy metals like mercury, lead, and cadmium, poses a significant threat to marine ecosystems. The research, involving water sample collection from ten different vessels across various countries, assesses physicochemical parameters and heavy metal concentrations. Results indicate variations in temperature, turbidity, conductivity, dissolved oxygen, and pH levels among samples. Turbidity values surpassing WHO limits suggest potential anthropogenic pollution. The study identifies significant differences in pH values, potentially influencing microbial populations. Total dissolved solids and total suspended solids values vary, affecting the distribution of potential pathogens. The results reveal varying total concentrations of heavy metals (mg/L) in the following decreasing order: SA>SE>SF>SB>SC>SD>SH>SI>SG>SJ(6.07 >4.95 > 2.07 > 1.59>0.24>1.22>0.0 9>0.04>0.03>0.01). The highest concentration of heavy metals is recorded for iron (SA= 5.78), zinc (mg/L) (SB = 1.36, SE = 1.30, and SF = 1.35) and lead (Pb) (SE = 2.39). The elevated iron levels in vessels from SA are potentially linked to corrosion processes. Cadmium, lead, and nickel were not detected, except for lead in the sample from SE. Copper concentrations were aligned with EU standards in the vessels. Proper ballast water management is vital for monitoring water qualities, preventing environmental spread of heavy metals, ensuring marine ecosystem health, and developing compliance strategies for ships docking in ports. 1. Introduction The release of ballast water containing degraded water quality and elevated levels of heavy metals, such as mercury, lead, and cadmium, into the ocean by ships can have severe effects for marine ecosystems (Dobaradaran et al., 2018). The bioaccumulation of these heavy metals in marine organisms poses a significant threat to organism health and survival, as they can enter the food chain and cause detrimental effects on biodiversity and ecosystem functioning. Moreover, the presence of pollutants such as oil, chemicals, and microplastics in ballast water can exacerbate these negative * Corresponding author: Department of Transport and Nautical Science, Nigeria Maritime University Okerenkoko, Warri, Delta State, Nigeria E-mail address: nwaogbe.obioma@nmu.edu.ng